odurandina

sir, that would be too easy.





start at post # 1077 — (or post # 1)...

https://rennlist.com/forums/968-foru...opment-72.html

Dubai944

Supercharging works just fine. It has been used as a legitimate way to add power to engines for decades. A lot of early race cars, world war 2 fighter planes, generations of drag racers, street racers and recently an increasing number of production car manufacturers have used it successfully. Personally I race a 968 powered 944 which is supercharged and it works very well for the type of racing I do after a lot of modification and development. I love the power characteristics which are much more like large NA motors compared to many turbocharged cars I have driven and raced.

It is silly to say supercharging doesn't work but turbocharging does. The problems everyone continually alludes to on this forum come about because of the naive notion that you can just bolt on a power adder like a supercharger and increase power output by 25, 50% or even more and still have total reliability and driveability without the bother of having to spend or develop anything else. There is no free lunch and any power adder requires the whole system to match it.

Done properly supercharging works fine, but not many have done it properly. There has not been much real effort at development for supercharging on these motors compared to the vast accumulated knowledge in decades of turbocharging the 944. Supercharger kit suppliers, with few exceptions, have just figured out how to physically bolt on a head unit, added a couple of pulleys and belts and advertise overly optimistic results. By contrast the turbo motors are already built by the factory to work as a system. Because of that it will inevitably be more expensive to arrive at a well set up supercharger arrangement on these motors than going the proven turbo route if you want anything more than a mild power increase.

You migh get away with a basic supercharger setup with a very low boost application of a few psi and be happy with the improved engine breathing and a little bit of added power, but most people expect a lot more power for the effort and thats where the dissapointments start. To do it properly you will have to build the engine for boost no different than a turbo engine.

If you want really decent long lasting power you will also have to solve the biggest problem in my opinion of belt drive systems which are difficult on this engine due to the tiny 5 inch diameter crank pulley, which means you need very small supercharger pulleys to get any boost which inevitably causes problems with belt slip, belt breakages, overworked charger and alternator bearings from having to run very tight belts etc etc.

I run a custom oversized 8 rib pulley system. I have a 7 inch crank pulley which required eliminating all the belt covers and converting to electric power steering, the motor is built as strong as any turbo motor with lowered compression, my engine is tuned with a Motec stand alone. It all works well, but it took a lot of development to get to this point and there is still work to do. And it wasn't any cheaper than turbocharging. It doesn't make any more power than a turbo motor would for the same boost levels either, but there are advantages in driveability, heat control and mechanical simplicity which I like for racing and, for my application, I am happy with the result. I probably wouldn't bother for a street car with mild power increases in mind, when it is so simple to swap in a turbo motor ready to go.

So the original posters who said you need money were right! But you need money to do any type of power improvements properly whether it is NA, turbo or supercharging so there should be no surprises there?

You need to control the tuning at least with a piggyback, and you need to build the motor to suit the level of boosted power output you want and you need a good belt system. If you do those things supercharging can work well.

MN

Sounds familiar for those who have followed the 928motorsport supercharger development for the 968 on rennlist!

Paulyy

i like the way you think!

MAGK944

It seems to me that supercharging is not the way to go with these cars. If you really want to do something a little different and get about the same power gains as a supercharger, why not develop an itb setup. The hardest part would be fabbing the intake pipes, aftermarket or used bike itbs are plentiful and relatively cheap. Control it all with a good standalone Tec3 etc and you should be making 200-250 of reliable hp. Plus, no need for forged internals, lowered compressions, belts or all that other stuff.

Dubai944

To make an itb setup make the same power gains as a low boost forced induction setup is hardly simple. itbs are even less of a bolt on power adder than a supercharger. By themselves you might gain some added throttle response. Without cams headwork and exhaust you won't benefit much from the potential extra flow and without revving the engine higher you won't make a lot more power. If you rev the engine harder you will start to affect the reliability of internal parts....again, it needs to be a complete system to work really well and the cost adds up. Compared to itbs a low boost supercharger or turbo setup will more easily flow the extra air without the need for the top end mods, and be easier to tune. If you only wanted 200-250hp without force induction just stick in a completely reliable stock 3.0 litre motor.

MAGK944

We really don't know as no real work has been done in this area on the base 944. Even with the stock cam and 40mm intakes I can see more than just a throttle response gain from itb's and decent engine management. Hell, just the tec3 and coil pack will help a lot. The flow restrictions of the stock intake and that stupid afm gone must produce good positive gains.

Off course we could go with a custom grind on the cam, use 1.880in (47mm) intake valves, port & polish the runners, even fit the later 10.2 or 10.6 euro pistons. But I would like to see someone at least attempt this on a stock engine.

The two big negatives for me on superchargers are you are adding a lot of wieght to the front of the car (charger, intercooler, pipes, pulleys, belts, etc) and you are using a lot of engine power to drive the thing in the first place. At least with itb's you are taking wieght away and not consuming any engine power to drive them.

I think the op wants a project, so I am gonna keep trying to push him to my way of thinking

Dubai944

Well at least itbs are pretty.....

MAGK944

Very purdy! and they sound a lot better than the constant drone and clatter of a supercharger.

968 for the record:

Dubai944

I disagree, I like the sound of my car...you can listen to it here and watch a brand new maserati V8 factory built race car with 8 itbs fail to stay in front of a 20 year old 944 with supercharging (which supposedly doesn't work on these cars...)


Sorry to the OP for threadjacking... I'm just doing my best to balance out the supercharger naysayers

blown 944

Oh don't worry, the lsx guys will be along soon enough to tell you what a fool you have been by not swapping in a gm :-)

Nice setup you have there. You are right on target with the engine intervals. However, there is a very nice option for tuning now available which helps out significantly. Choice of fuels also plays well into how well a bargain setup can do.

Yes it can be done, has been done, is fun... I like it myself.

MAGK944

Don't get me wrong I would love to see a supercharger setup on these cars, one that keeps the AC would be great (FL) and provides a decent boost on pump gas and doesn't require an engine build. Problem is I haven't seen one in the lifetime of the 944. There are a handful of good SC'd 944's out there all with different configurations but none of them meet my requirements.

As for itb's they have been talked about on this forum a lot over the years and I think it would be really cool if someone tried to do a base 944 build with them.

V2Rocket

i know a guy who developed a full bolt-on 968 SC kit years ago. i have seen the kit in person, it looks like it could be factory. kits are still available from him and he doesnt really make any money on them, he just pieces them together.

andys-944

I don't have to much to show so far but I should be starting a build thread soon. We are working on a SC set up for base NA's which will retain the AC.
The basic setup is a Eaton M62 SC, 951 intercooler, AFM replacement, custom manifold, brackets and pulleys and tensioner. Running 8 to 10 psi boost.
We will try this on my 944 with 225,000 miles on a un rebuilt motor and see how it goes Stage 2 will be a completely rebuilt motor but that's in the future.
My goal is to get a worthwhile performance gain for everyday driving we will be tuning everything on the dyno for performance and drivability.
The bottom line is almost all 944's have high mileage and could suffer a engine failure at any time even with out adding HP so it will be fun to see what happens Josh at Rogue tune has some interesting results on his website, that would be worthwhile taking a look at if you have interest SC's.
If this goes well we will look at selling kits but that in the future.

Lemming

I've got a used supercharger and all accessories that was on my 968 motor that I'll sell for a good price. I even have a selection of intercoolers that I'll throw in. PM me if interested. The SC is from 928 Motorsports.